From: Igor Plyatov <plyatov@gmail.com>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
f.fainelli@gmail.com, joe@perches.com, luwei.zhou@freescale.com,
richardcochran@gmail.com, davem@davemloft.net,
u.kleine-koenig@pengutronix.de, Fabio.Estevam@freescale.com,
LW@KARO-electronics.de, Frank.Li@freescale.com
Cc: Igor Plyatov <plyatov@gmail.com>
Subject: [PATCH] net: phy: workaround for buggy cable detection by LAN8700 after cable plugging
Date: Thu, 13 Aug 2015 16:12:36 +0300 [thread overview]
Message-ID: <1439471556-13760-1-git-send-email-plyatov@gmail.com> (raw)
* Due to HW bug, LAN8700 sometimes does not detect presence of energy in the
Ethernet cable in Energy Detect Power-Down mode (e.g while EDPWRDOWN bit is
set, the ENERGYON bit does not asserted sometimes). This is a common bug of
LAN87xx family of PHY chips.
* The lan87xx_read_status() was improved to acquire ENERGYON bit. Its previous
algorythm still not reliable on 100 % and sometimes skip cable plugging.
Signed-off-by: Igor Plyatov <plyatov@gmail.com>
---
drivers/net/phy/smsc.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index c0f6479..a380958 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -104,10 +104,12 @@ static int lan911x_config_init(struct phy_device *phydev)
static int lan87xx_read_status(struct phy_device *phydev)
{
int err = genphy_read_status(phydev);
+ int rc;
+ int i;
if (!phydev->link) {
/* Disable EDPD to wake up PHY */
- int rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
+ rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
if (rc < 0)
return rc;
@@ -116,8 +118,16 @@ static int lan87xx_read_status(struct phy_device *phydev)
if (rc < 0)
return rc;
- /* Sleep 64 ms to allow ~5 link test pulses to be sent */
- msleep(64);
+ /* Wait max 640 ms to detect energy */
+ for (i = 0; i < 64; i++) {
+ /* Sleep to allow link test pulses to be sent */
+ msleep(10);
+ rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
+ if (rc < 0)
+ return rc;
+ if (rc & MII_LAN83C185_ENERGYON)
+ break;
+ };
/* Re-enable EDPD */
rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
@@ -191,7 +201,7 @@ static struct phy_driver smsc_phy_driver[] = {
/* basic functions */
.config_aneg = genphy_config_aneg,
- .read_status = genphy_read_status,
+ .read_status = lan87xx_read_status,
.config_init = smsc_phy_config_init,
.soft_reset = smsc_phy_reset,
--
1.7.9.5
next reply other threads:[~2015-08-13 13:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-13 13:12 Igor Plyatov [this message]
2015-08-13 16:50 ` [PATCH] net: phy: workaround for buggy cable detection by LAN8700 after cable plugging Joe Perches
2015-08-13 17:11 ` Igor Plyatov
2015-08-13 17:15 ` Joe Perches
2015-08-13 18:37 ` David Miller
2015-08-13 19:23 ` Igor Plyatov
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